xbmc/windowing/OSScreenSaver.h

   1 /*
   2  *  Copyright (C) 2017-2018 Team Kodi
   3  *  This file is part of Kodi - https://kodi.tv
   4  *
   5  *  SPDX-License-Identifier: GPL-2.0-or-later
   6  *  See LICENSES/README.md for more information.
   7  */
   8
   9 #pragma once
  10
  11 #include <memory>
  12 #include <utility>
  13
  14 namespace KODI
  15 {
  16 namespace WINDOWING
  17 {
  18
  19 class COSScreenSaverManager;
  20
  21 /**
  22  * Inhibit the OS screen saver as long as this object is alive
  23  *
  24  * Destroy or call \ref Release to stop this inhibitor from being active.
  25  * The OS screen saver may still be inhibited as long as other inhibitors are
  26  * active though.
  27  *
  28  * \note Make sure to release or destroy the inhibitor before the \ref
  29  *       COSScreenSaverManager is destroyed
  30  */
  31 class COSScreenSaverInhibitor
  32 {
  33 public:
  34   COSScreenSaverInhibitor() noexcept;
  35   COSScreenSaverInhibitor(COSScreenSaverInhibitor&& other) noexcept;
  36   COSScreenSaverInhibitor& operator=(COSScreenSaverInhibitor&& other) noexcept;
  37   ~COSScreenSaverInhibitor() noexcept;
  38   void Release();
  39   bool IsActive() const;
  40   operator bool() const;
  41
  42 private:
  43   friend class COSScreenSaverManager;
  44   explicit COSScreenSaverInhibitor(COSScreenSaverManager* manager);
  45   bool m_active;
  46   COSScreenSaverManager* m_manager;
  47
  48   COSScreenSaverInhibitor(COSScreenSaverInhibitor const& other) = delete;
  49   COSScreenSaverInhibitor& operator=(COSScreenSaverInhibitor const& other) = delete;
  50 };
  51
  52 /**
  53  * Interface for OS screen saver control implementations
  54  */
  55 class IOSScreenSaver
  56 {
  57 public:
  58   virtual ~IOSScreenSaver() = default;
  59   /**
  60    * Do not allow the OS screen saver to become active
  61    *
  62    * Calling this function multiple times without calling \ref Unhibit
  63    * MUST NOT produce any side-effects.
  64    */
  65   virtual void Inhibit() = 0;
  66   /**
  67    * Allow the OS screen saver to become active again
  68    *
  69    * Calling this function multiple times or at all without calling \ref Inhibit
  70    * MUST NOT produce any side-effects.
  71    */
  72   virtual void Uninhibit() = 0;
  73 };
  74
  75 /**
  76  * Dummy implementation of IOSScreenSaver
  77  */
  78 class CDummyOSScreenSaver : public IOSScreenSaver
  79 {
  80 public:
  81   void Inhibit() override {}
  82   void Uninhibit() override {}
  83 };
  84
  85 /**
  86  * Manage the OS screen saver
  87  *
  88  * This class keeps track of a number of \ref COSScreenSaverInhibitor instances
  89  * and keeps the OS screen saver inhibited as long as at least one of them
  90  * exists and is active.
  91  */
  92 class COSScreenSaverManager
  93 {
  94 public:
  95   /**
  96    * Create manager with backing OS-specific implementation
  97    */
  98   explicit COSScreenSaverManager(std::unique_ptr<IOSScreenSaver> impl);
  99   /**
 100    * Create inhibitor that prevents the OS screen saver from becoming active as
 101    * long as it is alive
 102    */
 103   COSScreenSaverInhibitor CreateInhibitor();
 104   /**
 105    * Check whether the OS screen saver is currently inhibited
 106    */
 107   bool IsInhibited();
 108
 109 private:
 110   friend class COSScreenSaverInhibitor;
 111   void RemoveInhibitor();
 112
 113   unsigned int m_inhibitionCount{0u};
 114   std::unique_ptr<IOSScreenSaver> m_impl;
 115 };
 116
 117 }
 118 }